Question

A cylindrical tube has an outer diameter of 2.5cm and an inner diameter of 1.5cm. It's length is 7cm. If it has to be anti-rust coated on the outer side, the inner side and the rims on both sides, what is the total surface area to be covered for this purpose? Calculate the cost if the rate is $0.50 per cm²?​

Answer 1

Step-by-step explanation:

आराम से तन्हा कट रही थी तो अच्छी थी, ज़िन्दगी तू कहाँ दिल की बातों में आ गयी।

Answer 2

Answer:

Let the radius of inner perimeter be r

1

and the outer perimeter be r

2

So,

2r

1

π

2r

2

π

=

22

23

⇒r

2

=

22

23

r

1

Now from the question, we have

r

2

−r

1

=5

22

23

r

1

−r

1

=5

⇒r

1

=110

and r

2

=115

Area of path enclosed between two circles are,

=π(r

2

2

)−π(r

1

2

)

=π(115

2

−110

2

)

=3535.71

Thus the area of path enclosed between the two circles is 3535.71 sq. m.